Across the construction industry there are attempts to achieve maximum weight saving. This is especially true for structural bodies of moving objects that are subject to frequent acceleration and braking processes, for which weight saving leads to savings in energy and costs.
One branch of industry which is important in this context is the wind turbines sector. Rotor blades of wind turbines must be made of lightweight construction, in order to meet the requirements for efficient energy production.
A complicating factor, in particular in the offshore segment, is that wind turbines experience high erosive forces. Therefore, high-build (and hence weight-intensive) erosion protection coatings for lightweight components or lightweight-constructions are needed.
At the construction stage, the size of the objects, particularly of rotor blades, often entails the assembly of different, individually produced smaller components. The assembly of the individual components typically results in the presence of gaps and recesses, which have to be covered and/or leveled. A putty (filling compound) is used to provide a smooth and uniform surface that can suitably be coated with an erosion protection top coating. In view of the large quantity of putty needed for such smoothing or leveling, even a slight reduction in density of the putty results in significant weight saving.
There is a need for a putty that meets the basic requirements of a putty as a filling compound, whilst also resulting in a putty coating that is lightweight and therefore able to contribute to weight saving of the coated substrate.